There are now stable versions of mingw64 most notable gcc 4.7.0 versions
It should be fairly easy for you guys to create such a version given the fact that you create linux builds that use gcc
If you want you could send me the windows vs sln file and the linux makefile or cmake if you use that and I could adjust it to support mingw64. You don’t even need to send me the source to any code. Could have it done in half an hour or so.